Acne is a disease of the sebaceous hair follicles, often called pores. At the base of each hair follicle is a gland called the sebaceous gland, which produces sebum. Sebum is an oily substance that keeps the skin moist and pliable, which under normal circumstances travels along the hair follicle to the surface of the skin. A blemish begins approximately 2-3 weeks before it appears on the skin's surface. As the skin renews itself, the old cells die and slough off. When cells are shed unevenly and clump together with the sebum it forms a plug. Sebum which normally drains to the surface gets blocked and bacteria begin to grow. The rapid growth of the bacteria in combination with the accumulated sebum cause the follicle to enlarge and result in a mild form of acne called comedones, which are non-inflammatory. Both whiteheads and blackheads start out as a “microcomedone” and then become skin blemishes called comedones, either a whitehead or a blackhead. Acne is trapped sebum and bacteria (propionibacterium acnes) growing in a plugged follicle. Sebaceous glands are most numerous on the face, chest, back, neck and scalp; consequently, these are the most common sites of acne. The most common factors that cause acne are hormones, increased sebum production, bacteria (Propionibacterium Acnes), and changes inside of the hair follicle. Acne may progress to an inflammatory type of acne lesions that are red in color called papules, pustules and nodules.
There are many types of acne, ranging in severity from mild to severely disfiguring. Acne vulgaris is the most common form of acne which includes several types of pimples. These acne lesions include blackheads, whiteheads, papules, pustules, nodules and cysts.
Mild to moderate acne vulgaris is characterized by whiteheads, blackheads, papules, and pustules. A whitehead is formed when a pore is completely blocked, trapping sebum, bacteria, and dead skin cells below the skin surface causing a white appearance on the surface. Whiteheads are normally quicker in life cycle than blackheads. A blackhead is formed when a pore is only partially blocked, allowing some of the trapped sebum, bacteria, and dead skin cells to drain to the surface slowly. The black color is due to a reaction of the skin's own pigment, melanin, reacting with the oxygen in the air. A blackhead tends to be a stable structure. Blackheads can often take a long time to clear because the contents very slowly drain to the surface. Papules are small, red, tender bumps with no head. Papules are the earliest stage in the development of what are normally considered the typical “pimple”. Papules are an intermediate in the progression of acne between the non-inflammatory and inflammatory stages. Pustules are similar to whiteheads, but are inflamed, and appear as a red circle with a white or yellow center.
Severe acne vulgaris is characterized by nodules and cysts. Nodular acne consists of acne spots which are much larger, can be quite painful, and can sometimes last for months. Nodules are large, hard bumps under the skin's surface. Scarring is common with nodules. An acne cyst can appear similar to a nodule, but is pus-filled, and can been described as having a diameter of 5 mm or more across. They can be painful and scarring is common with cystic acne.
Acne rosacea can look similar to the aforementioned acne vulgaris, and the two types of acne are sometimes confused for one another. Rosacea affects millions of people, most of whom are over the age of 30. It appears as a red rash which is normally confined to the cheeks, nose, forehead and chin. The redness is often accompanied by bumps, pimples, and skin blemishes. Blood vessels may also become more visible on the skin. Blackheads are not a part of rosacea. It is more prevalent in women, but often more severe when found in men. Left untreated, it can cause swelling of the nose and the growth of excess tissue, a condition called rhinophyma.
Acne conglobata is the most severe form of acne vulgaris and is more common in males. It is characterized by numerous large lesions, which are sometimes interconnected, along with widespread blackheads. It can cause severe, irrevocable damage to the skin, and disfiguring scarring. It is found on the face, chest, back, buttocks, upper arms, and thighs. The age of onset for acne conglobata is usually between 18 and 30 years, and the condition can stay active for many years.
Acne fulminans is an abrupt onset of acne conglobata which normally afflicts young men. Symptoms of severe nodulocystic, often ulcerating acne are apparent. As with acne conglobata, extreme, disfiguring scarring is common. Acne fulminans is unique in that it also includes a fever and aching of the joints.
Gram-negative folliculitis is a bacterial infection characterized by pustules and cysts, possibly occurring as a complication resulting from a long term antibiotic treatment of acne vulgaris. It is a rare condition, and prevalence in males versus females is unknown.
Pyoderma Faciale is severe facial acne affects only females, usually between the ages of 20 to 40 years old, and is characterized by painful large nodules, pustules and sores which may leave scarring. It begins abruptly, and may occur on the skin of a woman who has never had acne before. It is confined to the face, and usually does not last longer than one year, but can wreak havoc in a very short time.
Teenage (adolescent) acne: Most cases of acne that require treatment occur in individuals 9 to 19 years of age. Boys and girls are equally affected but the condition is usually more severe in boys. No ethnic groups are predisposed to acne, but certain cosmetic practices, such as the use of oily grooming agents, can lead to a specific pattern of lesions. Internal factors that may cause adolescents acne include endogenous hormones (androgens, progesterone) and specific drugs (oral contraceptives, isoniazid, phenytoin, corticosteroids, lithium-containing compounds). External factors include skin bacteria, especially Propionibacterium acnes; industrial chemicals (petroleum, animal and vegetable oils); oil- or wax-containing cosmetics; greasy sunscreen or suntan preparations; and local pressure from objects such as headbands, shoulder pads, or helmets. Excessive perspiration and emotional stress can also aggravate acne. Androgens (e.g., testosterone) will increase the size of sebaceous glands and, in people prone to acne, increase the production of sebum. In women, fluctuations in estrogen during the menstrual cycle change the sensitivity of sebaceous glands to androgens. During puberty, the skin cells lining the follicle shed more quickly, mix with the increased levels of sebum and increase the likelihood of the pores becoming clogged.
Adult acne: Twenty percent (20%) of the adult population is afflicted by adult acne, most of them women. Modern-day job related stress, pollution, poor nutrition and bad cosmetics are among the major contributing factors. A common case of adult acne consists of blackheads and whiteheads, while others developed inflamed acne papules or pustules.
Approximately 85% of people worldwide suffer from acne at some point in their lives, leading to more than 103 million affected by acne at any given moment. Approximately 17 million people in the U.S. have acne resulting in approximately 5.5 million visits to the physicians each year.
Acne vulgaris occurs in up to 95% of the population in westernized societies; acne vulgaris is a nearly universal skin disease afflicting 79% to 95% of the adolescent population. In men and women older than 25 years, 40% to 54% have some degree of facial acne, and clinical facial acne persists into middle age in 12% of women and 3% of men. (Cordain L, Lindeberg S, Hurtado M, Hill K, Eaton S B, Brand-Miller J. Acne vulgaris: a disease of Western civilization. Arch Dermatol 2002 December; 138(12):1584-90).
Current medications include a variety of topical and systemic medications such as antibiotics, anti-infectives, anti-inflammatories, hormone therapies, keratolytics, and retinoids. The over the counter medication include benzoyl peroxide, salicylic acid, sulfur, and resorcinol.
Benzoyl peroxide medication is very effective for killing acne-causing bacteria. Benzoyl peroxide first saw use in the 1930's, and remains a mainstay of acne treatment because it has proven itself to work well. To this day, benzoyl peroxide actually kills propionibacterium acnes (P. Acnes) better than any other medication on the market, prescription or otherwise. Benzoyl peroxide is available in non-prescription concentrations of 2.5%, 5% and 10%.
Many anti-acne agents, including benzoyl peroxide, have a high flux into the skin. While this penetration is advantageous during the initial application, the rapid subsequent diffusion in the skin means that the anti-acne agent will diffuse away from the acne lesion to be treated (a phenomenon known as “outflow”). In turn, this means that the efficacy of the anti-acne agent is lessened, because of the relatively short dwell time of the anti-acne agent in the area of the acne lesion. Thus, it would be advantageous to have a method and a kit that would decrease the outflow of the anti-acne agent from the area of the acne lesion.